Touch device and touch projection system using the same

摘要

A touch device including a light guide unit, a light emitting unit, an invisible light filter and an invisible light detector is provided. The light guide unit has at least one light incident surface and a first surface connected to the light incident surface. The light emitting unit is disposed beside the light incident surface and is capable of emitting an invisible light beam. The invisible light filter is contacted tightly with the first surface. The light guide unit is disposed between the invisible light filter and the invisible light detector. Moreover, a touch projection system including the touch device is also provided.